The present invention relates to compressors that are used in vehicle air conditioners. More particularly, the present invention relates to a compressor that includes a valve device such as a control valve for controlling displacement of the compressor.
A typical variable displacement compressor includes a drive shaft that is rotatably supported in its housing. The housing includes a cylinder block having cylinder bores. Each cylinder bore reciprocally houses a piston. A crank chamber is also defined in the housing. The crank chamber accommodates a swash plate. The swash plate is supported on the drive shaft to rotate integrally with and to tilt with respect to the drive shaft. Rotation of the swash plate reciprocates the pistons thereby causing the pistons to draw refrigerant gas from a suction chamber into the cylinder bores and to compress the gas. The pistons then discharge the compressed gas from the cylinder bores to a discharge chamber.
The discharge chamber is connected with the crank chamber by a supply passage. The supply passage includes a displacement control valve. The control valve regulates the supply passage for controlling the amount of refrigerant gas supplied from the discharge chamber to the crank chamber thereby controlling the pressure in the crank chamber. Changes in the pressure in the crank chamber alter the pressure difference between the crank chamber and the cylinder bores. The alteration of the pressure difference changes the inclination of the swash plate. Accordingly, the displacement of the compressor is varied.
The control valve typically protrudes from the lower side of the compressor housing so that the control valve does not interfere with other parts in the compressor or with other devices in the engine compartment. However, if the compressor is carelessly placed on a surface, for example, of a workbench, the lower end of the control valve contacts the surface. The weight of the compressor acts on the control valve and may deform the control valve. The deformation may cause the valve to malfunction. Further, the control valve can be loosened with respect to a corresponding recess in the compressor housing. This may cause the pressure in the compressor to leak to the outside. Thus, during storage or transport, an assembled compressor needs to be placed on a supporting tool or in a transport case such that the control valve does not contact a surface, which makes the handling of the compressor troublesome.